LED Through Electrodes Insulating Layers Current Crowding

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Solution Overview

Problem

Light-emitting diodes (LEDs) experience current crowding and non-uniform luminous efficiency due to strong luminescence coupling near electrode pads, leading to reduced light emission uniformity and shortened lifetimes.

Innovation Solution

A light-emitting element design featuring a first semiconductor layer, an active layer, and a second semiconductor layer, with through electrodes and insulating layers that gradually increase in area and diameter away from the electrode pad, reducing current crowding and improving heat management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrode pads are formed by etching a portion of the light-emitting structure, then electrical connection is achieved, but current crowding phenomenon occurs in regions adjacent to the electrode pad

Engineering Contradiction:
Improveelectrical connectionVSAvoidcurrent crowding
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The insulating layer is selectively positioned at specific locations (between the electrode pad and active layer, and between electrode pad and second semiconductor layer) rather than uniformly across the entire structure. This localized insulation approach addresses current crowding in critical regions while maintaining electrical connectivity where needed, demonstrating the local quality principle by applying different properties to different parts of the system.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If current is applied to the light-emitting element, then light emission occurs, but non-uniform luminous efficiency reduces light emission uniformity

Engineering Contradiction:
Improvelight emissionVSAvoidluminous efficiency uniformity
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The insulating layer acts as an intermediary element between the electrode pad and the light-emitting layers (active layer and second semiconductor layer). It mediates the current distribution by providing electrical insulation in regions where current crowding would otherwise occur, thereby enabling more uniform current flow and improving luminous efficiency uniformity while maintaining overall light emission functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If through electrodes are used to electrically connect the first semiconductor layer, then electrical conductivity is improved, but heat generation characteristics deteriorate

Engineering Contradiction:
Improveelectrical conductivityVSAvoidheat generation
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The insulating layer extracts or removes the harmful effect of heat generation by positioning itself between the through electrodes and the light-emitting structure. This insulation layer acts as a thermal barrier that prevents excessive heat transfer to sensitive regions, thereby managing heat generation characteristics while preserving the electrical conductivity function of the through electrodes.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3306680B1Light-emitting element
Publication Date: 2020.03.04 LG INNOTEK CO LTD
  • EP3306680B1 patent drawingFigure 1
  • EP3306680B1 patent drawingFigure 2
  • EP3306680B1 patent drawingFigure 3

AI summary

Disclosed according to one embodiment is a light-emitting element comprising: a light-emitting structure comprising a first semiconductor layer, an active layer, and a second semiconductor layer; a second conductive layer electrically connected to the second semiconductor layer; a first conductive layer comprising a plurality of through electrodes electrically connected to the first semiconductor layer through the second conductive layer and the light-emitting structure; an insulation layer for electrically insulating the plurality of through electrodes from the active layer, the second semiconductor layer, and the second conductive layer; and an electrode pad disposed in an exposed area of the second conductive layer, wherein the plurality of through electrodes differ in the area of a first region electrically connected to the first semiconductor layer.